Fig. 3

CLDN6 expression is down-regulated drastically correlating with histone deacetylization in breast cancer cells. a RT-PCR was determined effects of TSA treatment on CLDN6 expression in MCF-7 cells. TSA application induced CLDN6 expression in a concentration- and time-dependent manner. Lane 1 was control group, lanes 2 to 6 were TSA treated group (2: 75 nM; 3: 125 nM; 4: 250 nM; 5: 500 nM; 6: 1000 nM). Data in lane 3 showed that 125 nM TSA had the greatest effect on inducing expression of CLDN6. b CLDN6 expression in MCF-7 cells treated with 125 nM TSA for 1 to 72 h. Lane 1 was control group, lane 2 to 6 were 125 nM TSA treated group (2: 12 h; 3: 24 h; 4: 48 h; 5: 72 h). Data in lane 5 showed that 125 nM TSA for 48 h had the greatest effect on inducing expression of CLDN6. c Western blot assay examined CLDN6 protein expression was significantly up-regulated in MCF-7 cells treated with TSA at 125 nM for 48 h. d Immunofluorescent staining showed expression of CLDN6 at the membranes of MCF-7 cells treated with 125 nM TSA for 48 h using × 100 magnification. e RT-PCR was used to determine the expression of CLDN6 in MCF-7cells treated with 5-aza-dC and TSA respectively or synergistically. f Western blot assay examined CLDN6 protein expression in MCF-7cells treated with 5-aza-dC and TSA respectively or synergistically. g Immunofluorescent staining showed expression of CLDN6 at the membranes in MCF-7 cells treated with 5-aza-dC and TSA respectively or synergistically using × 400 magnification. CLDN6, claudin-6; TSA, Trichostatin A; 5-aza-dC, 5-Aza-2’-deoxycytidine